Process for the co-production of ethanol and an improved human food product from cereal grains

ABSTRACT

A process for producing a novel cereal grain food product is disclosed. This novel food product is high in fiber and protein with an unsweet dextrin coating that renders the product good-tasting and suitable for human consumption. This process involves the enzymatic conversion and removal of starch from the grain. The converted grain is separated from its liquor before the liquor is fermented to produce ethanol. The food product may be incorporated into baked goods, drinks, breakfast cereals and the like or eaten &#34;as is&#34;.

The products and process of the present invention relate to recoveringhuman food value from the residues remaining after starch containingcereals and the like have been converted to sugar during the productionof ethanol. More particularly, the invention relates to compatiblyproducing an industrial grade ethanol and a high-fiber, high-proteinfood product which is suitable for human food use.

BACKGROUND OF THE INVENTION

Perhaps one of the oldest industrial chemical processes is theproduction of ethanol from starchy agricultural products using naturalenzymes and yeast. This process has been utilized by brewers anddistillers for centuries and is currently of special commercial interestin the well-known industrial production of fuel grade alcohol fromgrain.

It is well known that brewers of beer preferably use malted barley. Onedesireable difference between barley and other common cereals is thatthe husk adheres to the kernel after threshing. This feature makes theprocess of malting and subsequent extraction of the wort much easierthan with wheat or other grains.

In the beer-making process, great care is taken to make sure thatcrushing occurs over the whole length of the kernel. This preserves thehusk almost intact to aid in filtration. A careful balance betweenextraction efficiency and filtration efficiency must be met.

Ancient experience teaches that if the husks of the malted barley arecrushed too finely, leaching of bitter materials from the husks impartsundesirable flavor and shortened shelf life to the beer. On the otherhand, beer produced entirely from dehusked malt has a veryunsatisfactory flavor. Accordingly, the husks of the malted barley are anecessary part of the brewers' art.

Prior to fermentation, the brewer separates the sweet wort from thespent grains utilizing the coarse husks as a filter material. Thisfiltering should take place rapidly with substantially all sugars washedout of the spent grains.

The very process steps necessary to produce fine beers, result in spentgrain having unacceptable organoleptic characteristics. The necessity ofleaving the husk of the malted barley intact results in the spent grainsbeing course and rough. The required chemical changes during maltingwhich gives the beer satisfactory flavor, leaves the husk bitter andorganoleptically unacceptable for human food use.

A further requirement of good beer-making practice, which hasdetrimental effects on spent grains as a human food, is a result of thechanges made in the proteins in the mash. The malted barley alsocontains protein-degrading enzymes, notably protease, which convertsproteins into peptides and amino acids during mash digestion. Thesenitrogeneous peptides and amino acids are soluble and are filtered awayfrom the spent grains to be used in the wort. This generally results inlower protein levels in the spent grains. These nitrogenous materialsare later precipitated from the fermented beer and added back to thespent grains, which increases bitterness because of exposure to thefermentation process.

Currently, corn is the most popular grain used to commerciallymanufacture fuel alcohol. The process typically involves a two-stageenzymatic conversion of starch to sugar, followed by fermentation andthen distillation to recover alcohol and carbon dioxide. Manufacturerstypically dry the grain residue and sell the dried product, commonlycalled "Distillers' Dried Grains," as an animal feed or as a componentof animal feed products. The soluble portion of the residue is oftendried separately.

At the present time, wheat or other grains are not an economical choiceas a fermentation substrate unless the spent grain can be sold for ahigher price as human food rather than animal feed. Wheat residues aregenerally higher in protein, lysine, and threonine than corn residues.The process for manufacturing alcohol from wheat is very similar to thatof corn.

Utilization of alcohol production residues have received littleapplication beyond use in animal feeds. A major problem with distillers'grain residue is that it possesses a distinct odor and taste whichnegatively affects acceptability even for use in animal feed. Manyattempts have been made throughout the years to find acceptable humanfood grade applications for Distillers' Dried Grains and Brewers' SpentGrains, but without success. For a thorough discussion of the use ofDistillers' Dried and Brewers' Spent Grains in human food, see U.S. Pat.No. 4,828,846 to Rasco, et. al. which is hereby incorporated byreference.

Rasco, et. al. teaches that the unpleasant taste and odor of Distillers'Dried Grains may be masked or reduced by the careful adjustment of pH bysuitable acids and bases during starch conversion and before drying. Thespent grains so treated may be used in human food products. Although animprovement over the dried grains of the typical alcohol productionprocess, these products have proven only marginally successful. Thegrain products so produced still have an unacceptable taste and must be

SUMMARY OF INVENTION

In the product of the present invention a high fiber, high protein foodproduct is produced which is organoleptically suitable for humanconsumption. This food product comprises milled starch-bearing cerealgrains which have had 90 to 100% of the starch enzymatically converted.These converted cereal grains have a protein content on a dry matterbasis substantially between 17 to 30% by weight. These converted grainsalso have a total dietary fiber content on a dry matter basissubstantially between 30 to 70% by weight and a nitrogen-free extractcontent on a dry matter basis less than 40%. Further, the grains have acoating of residual sugars thereon from the enzymatic conversion ofstarch which is 17 to 30% by weight on a dry matter basis.

In the process of the present invention a high protein, high fiber foodproduct which is organoleptically suitable for human consumption isproduced from starch-bearing cereal grains. The process comprises thesteps of suspending the cereal grains in a selected amount of water toform an aqueous slurry, heating the slurry, liquifying and hydrolyzing aselected amount of the starch and separating the grain solids fractionfrom the aqueous fraction to produce a substantially solids-free aqueoussugars fraction and solids cake. In this process, the aqueous slurry isheated sufficiently to at least partially gelatinize the starch.

During the liquifying and hydrolyzing of the starch with enzymes, theselected amount of starch hydrolyzed is between 90 to 100% whichproduces a grain mixture to be separated. The aqueous sugars fractionseparated from this mixture has a Brix value substantially between 14 to24 degrees.

The grain solids cake separated from this mixture has a so-lids contentsubstantially between 30 to 50% by weight and an aqueous sugar fractioncontent substantially between 50 to 70% by weight. This grain solidscake has a total dietary fiber content on a dry matter basissubstantially between 30 to 70% by weight, a protein content on a drymatter basis substantially between 17 to 30% and a nitrogen-free extractcontent on a dry matter basis of less than 40% by weight.

The food products of the present invention also include baked goods madewith cereal flour containing the above described high fiber, highprotein food product in an amount equal to 15 to 50% by weight of thecereal flour. Other food products of the present invention compriseeither ready-to-eat or cooked cereal including the above described highfiber, high protein food product. Yet other food products of the presentinvention include high fiber, high protein food products made by theprocesses above described.

It is an object of the present invention to increase the added value ofthe products used in the production of grain alcohol for fuel use bysimultaneously producing a higher value added spent grain product thanheretofore possible.

It is another object of the present invention to produce anorganoleptically acceptable grain product during the industrialproduction of grain alcohol which is high in fiber and protein.

It is yet another object of the present invention to produce a grainproduct from grains specifically blended to produce an ideal solublefiber to insoluble fiber ratio while maintaining highly acceptableflavor.

It is yet another object of the present invention to produce a grainproduct having sufficient flavor to be consumed "as is" or as a partialsubstitute for flour.

It is yet another object of the present invention to produce a humangrade food product of highest quality while simultaneously producingindustrial grade alcohol without the requirement of a complete foodgrade production system.

DISCUSSION OF THE BEST MODE OF THE INVENTION

In a preferred process of the present invention high quality grain isproperly cleaned and aspirated to remove any foreign material bothlarger and smaller than the grain kernel. The grain is then measuredprecisely and ground to uniform particle size. This insures consistencyin the cooking and drying steps, and optimal water, heat and enzymepenetration without contributing to the difficulty of separation fromthe liquor. Grain ground to a substantially uniform size of 60 mesh isbelieved to be preferred. It is understood that this milled grain mayconsist of wheat, corn, milo, pearled barley, psyllium, millet, rice,rye, sorghum, oats, and other starch-bearing grain, either alone or incombination, without departing from the process of the presentinvention.

The milled grain or grains is slurried with a selected amount of waterin a cooking vessel and then vigorously agitated to produce a completelyhomogeneous slurry. A homogeneous mixture insures that the particles ofmilled grain in the slurry are heated uniformly and have optimal contactwith the water. This slurry typically has a solids content between 20 to50 percent to ultimately produce a convenient concentration of sugar inthe liquid portion.

The slurry is then heated by a conventional means, such as steaminjection, to the gelatinization temperature of the selected grain.Although gelatinization temperatures will vary from grain to grain, thegelatinization temperature of typical grains range from 140 to 170degrees F. Although complete gelatinization is preferred, partialgelatinization is acceptable. However, it should be understood thatpartial gelatinization greatly increases the amount of time required forconversion of the selected amount of starch.

As the grain slurry approaches the gelatinization temperature, the solidstarch granules begin to swell. This swelling breaks apart the structureof the starch and forms an unstable suspension of high molecular weightglucose polymers, which are now exposed to breakdown by enzymaticaction. At this point, the slurry is in the form of a thick paste orgel, which has thickened considerably and is ready for hydrolysis.

Preferably, one or more alpha-amylase enzymes is used for liquifying andconverting the starch to sugars. These enzymes act to break down thelong glucose polymer chains, which make up the starch, into shortermolecular chains called dextrins. Once a glucosyl bond is broken, thealpha amylase is released and is available to repeat the process withother long glucose chains yet unbroken. Repeated hydrolysis of theglucose polymer chain at different points breaks the starch into smallerand smaller dextrin chains. Accordingly, if conditions remainedfavorable and enough time were allowed, many of the glucose polymerchains would be broken into individual glucose molecules.

For the purpose of the present invention, such extensive breakdown isundesirable. A high amount of glucose relative to total dextrinsproduces stickiness, excessive nitrogen-free extract, dryingdifficulties, and an undesired darker color in the final grain product.Proper selection of enzymes can adequately promote the liquification ofthe starch without excessive glucose formation. In contrast, theindustrial alcohol production processes of the prior art activelypromote the complete hydrolysis of the starch to glucose. It ispreferred in the present invention that the percent of glucose in thesugars remains low; preferably below 5%, and more preferably below 1%.

It is preferred that the selected enzyme be added before thegelatinization temperature of the grain is reached to insure thoroughmixing, but it is understood that the enzyme may be added at any time.Many enzymes which are well known in the art are believed acceptable forstarch liquification and conversion in the above process including alphaamylases, proteases, pectinases and amyloglucosidases. A particularlysuitable enzyme is available from Alltech, Inc. of Lexington, Kentuckyand sold under the trademark DEX-ZYME.

A useful characteristic of enzymes is that their operation is extremelytemperature sensitive. Below a certain temperature they aresubstantially inactive. Above a higher temperature they are irreversiblydestroyed.

Once the selected enzymes have been added according to manufacturer'sinstructions and the gelatinization temperature is reached, the heatingis temporarily halted and the degradation of starch is allowed toprogress. Because of the thickening of the slurry, it is recommendedthat vigorous agitation be applied throughout the starch removalprocess. The preferred temperature range of the slurry during hydrolysisis from 170 degrees F to 190 degrees F.

It is a feature of the present invention that substantially all (90 to100%) of the starch be hydrolyzed, but preferably the enzymatic actionshould be halted before the quantity of glucose molecules exceeds arange of 1% to 5%. The progress of the degradation of the starch may bemonitored by several simple methods, alone or, more preferably, incombination. These tests are the conventional starch-iodine test and theBrix specific gravity test for measuring sugar concentration.

The starch-iodine test is a procedure to determine the presence of rawstarch in the cooked grain slurry. Five or six drops of stock potassiumiodide and iodine solution is added to a test tube with water. Two orthree mls of the slurry to be tested is added to this solution. Aftershaking, a blue color indicates the presence of starch. Accordingly, theabsence of any bluish tint indicates complete starch conversion.

The Brix test is a measure of dissolved solids in solution. Thesedissolved solids may include proteins and inorganic salts, but arepredominantly mono-, di-, tri-, and poly-saccharides. There is no simplemethod for quantifying these sugars, but the Brix test offers aqualitative check on the amount of sugars solubilized through this stageof the process. Brix may be measured with a Brix, Balling, or specificgravity hydrometer, or a temperature compensating refractometer.

The preferred enzymes are those which break down the long starchpolymers quickly but do not excessively promote the formation of glucosemolecules. The cessation of enzymatic activity before excessive glucosemolecules are produced is easily accomplished by several alternativemethods. One method entails destroying the enzyme once the slurry testsat the selected level of starch conversion. This irreversibledestruction of the enzyme is affected by reheating the slurry veryrapidly to a temperature above the maximum temperature tolerance levelof the enzyme or "kill-point." This temperature varies from enzyme toenzyme, but it is preferred that the selected enzyme have a narrowactivity range for easy destruction. Conveniently, this temperature maybe between 190 degrees F. to 210 degrees F. In the alternative, thehydrolysis may be arrested by quickly separating the grain from theslurry and drying.

Once the necessary temperature is obtained to inactivate the enzyme, theslurry is much less viscous. No matter how the enzyme is inactivated, itis a critical feature of the present invention that the grain solids areseparated from the aqueous sugar fraction before fermentation. Contraryto the prior art, it is extremely important that no part of theprospective food product ever be subjected to the fermentation process.

The grain solids consist of insoluble protein portions of the grain,fiber and, optionally, a small amount of unconverted starch. The aqueousliquid consists of the soluble portion of the grain including someproteins and sugars, (i.e. the higher dextrins and glucose) that havejust been obtained by the hydrolysis of the starch. Typically, thesesugars are composed of 99% higher dextrins and less than 1% glucose.

As mentioned earlier, the amount of starch selected to be removed isbetween 90 to 100%. In some embodiments of the present invention, it maybe desired to leave some starch in the grains to aid in the dryingprocess. Naturally, if this is done, the relative amount of protein andfiber will be proportionately reduced. Accordingly, the least amount ofresidual starch necessary for drying enhancement is preferred. A removalof 98% of the starch is adequate for most purposes so it is thereforemost preferred.

In other embodiments of the present invention complete removal of starchis preferred. Accordingly, it has been found preferred that thehydrolysis should be stopped as quickly as possible after the cookedslurry tests "starch negative" using the starch-iodine test. This"starch negative" point is treated as 100% removal of starch. Again, thehydrolysis of larger dextrins into glucose continues after "starchnegative", so the arresting of hydrolysis is preferred before the amountof glucose reaches 5% of the total sugar.

The grain solids may be removed from the aqueous sugar fraction by anyconventional method, but centrifugation has been found particularlydesirable to form the solids cake. This solids cake contains the fiberand protein plus a certain amount of dextrins retained in the liquidwith the solids. However, it is understood that too much dextrinsretained in the solids will proportionally lower the protein and fibercontent of the finished product. A preferred amount of dextrin remainingon the solids product is between 17 to 30% by weight on a dry basis. Apreferred level of nitrogen free extract on a dry weight basis is lessthan 40% with, with less than 30% more preferred and less than 20% mostpreferred.

One of the reasons centrifugation has been found particularly desirableis that the residual sugar content may be easily controlled. Typically,the solids are removed from the centrifuge as a pumpable solids cakehaving about 30 to 50% solids, which mean that 50 to 70% of the solidscake is sugar water with a Brix between 14 and 24 degrees. Therefore, itis understood that the sugar content of the final product will vary notonly with the Brix of the aqueous fraction but also by the selectedsolids content of the solids cake. Although a Brix value between 14degrees to 24 degrees is acceptable, it may be preferred to select awater to grain ratio to produce a Brix value of 18 degrees to 21degrees. To conveniently produce a product having a nitrogen-freeextract of less than 30% when the starch is 100% hydrolyzed, a Brixvalue of 17 degrees to 19 degrees is more preferred.

Residual sugar is an important feature of the present invention andshould be controlled to maintain the sugar content of the final productabove 10%. Sugar contents substantially above 30% result in unnecessarycaloric content, reduced relative protein and and fiber and dryingproblems. Accordingly, the residual sugar content of the final productshould be between 10 to 30% with 17 to 30% more preferred and 18 to 22%most preferred.

It is modern convention to characterize grain products by measuring thecontent of protein, total dietary fiber, ash, fat and nitrogen-freeextract, as a weight percent on a dry matter basis. The nitrogen-freeextract includes total sugars, starches and everything not accounted forin the other catagories. This is calculated by subtraction and issometimes reported as "carbohydrates." Accordingly, for convenience andconformity, residual sugar, and unconverted residual starch if any, arecombined and reported as nitrogen-free extract. When residual sugarvalues are reported, the value is calculated by a suitable method, suchas mass balance, and does not include any starch.

In order to maintain the desirable characteristics of the product of thepresent invention, the drying process should be carefully monitored toprevent scorching or discoloration. Accordingly, the cake should bedried quickly and at the lowest convenient temperature, preferably notto exceed 170 degrees F.

The amount of moisture remaining in the dried product can affect thecolor and shelf life of the product. A moisture content below 10% ispreferred in order to prevent the onset of mold in storage. However, itis inconvenient to reduce the moisture level substantially below 2%because of the residual sugar coating. Accordingly, a moisture contentbetween 2 to 10% is desired with 4 to 8% more preferred.

The cake may be dried by any appropriate low-temperature dehydrationprocess, such as drum dryers, flash dryers, spray dryers, or the like.The texture of the final product is affected by the drying process, witha flake usually preferred over a granule. Spray dryers tend to producegranules but drum dryers have proven to be particularly desirable for aflake-like final product.

It should be noted that the process of the present invention result inthe enzymatically reduced grain being coated or encapsulated by theresidual sugars. This coating, together with the cooking and degradationprocess described earlier, acts to smooth the otherwise rough and jaggedparticle to enhance the "mouthfeel" of the product and overcome theunpleasant coarseness heretofore associated with bran products. Further,the coating acts to isolate the tongue from the bran hereby reducing theharshness of the bran flavor. It should be remembered that the residualsugars of the coating are particularly rich in less sweet, higherdextrins relative to the sweeter glucose and therefore does not promotean inappropriate oversweetness in the finished product.

The solids-free aqueous sugar fraction from the above separation has asugar content as indicated by a Brix value of approximately 14 to 24degrees. This aqueous sugar fraction, or sweet wort, is now pumped to anappropriate vessel and a thermostable alpha-amylase, such as ALLCOHOLASEHIGH T (Alltech, Inc. Lexington, Kentucky) is added and the aqueoussugar solution is heated to 190 to 200 degrees F. This enzyme additionwith heating will hydrolyze the higher dextrins and any unconvertedstarch to produce a minimum of 3 to 5% glucose in the sugar fractionwhich is preferred for initial fermentation. The sweet wort is held atthis temperature for approximately one hour. In the alternative, theaqueous sugar fraction may be cooled and pumped directly to thefermenters, although this is not preferred.

Following the pre-fermentation heating and holding period, thesolids-free aqueous sugar fraction may now be transferred to thefermenter. The sugar fraction is first cooled to a temperature of 90degrees F. It is typically innoculated with: (a) penicillin; (b) 0.02 to0.03% amyloglucosidase enzyme such as ALLCOHOLASE II (Alltech); (c) ayeast; and (d) yeast nutrients. The fermentation step is carried tocompletion in a conventional manner over a period of 24 to 48 hours. Thealcohol is removed from the fermentation beer by distillation to producesubstantially pure (95%) grain alcohol. The stillage from thisdistillation contains yeast cells and any unfermented solubles containedin the aqueous sugar fraction. The yeast cells are particularly high inby-pass proteins and make a valuable cattle feed ingredient whencombined with low-quality roughage.

EXAMPLE ONE

Number 2 red wheat was ground in a hammermill with an 8/64th inchscreen. Four thousand pounds of this milled grain was added to 1,850gallons of water at 68 degrees F and stirred. This produced a grainslurry having a solids content of 21% by weight. According tomanufacturer s instructions, calcium in the form of three pounds offood-grade lime was added to the water to provide a free calcium ion toenhance the viability of the enzyme. The slurry was heated by directsteam injection until a temperature of 80 degrees F was obtained and sixpounds of DEX-ZYME was added (0.15% by weight of the grain used).

Heating with stirring was continued until a temperature of 180 degrees Fwas obtained and the slurry was maintained at that temperature forapproximately 24 minutes. A conventional starch iodine test indicatedonly a slight presence of starch in the slurry with a Brix value of 19.5degrees.

Steam was again injected into the slurry until the slurry obtained atemperature of 200 degrees F and the steam was shut off. This heatingwas sufficient to destroy the enzyme and arrest hydrolysis. Aconventional starch-iodine test now indicated "starch negative" and aBrix value of 20.5 degrees was measured. At this point, the slurry hadan aqueous sugar fraction composed of 99.7% dextrins and 0.3% glucose.

The slurry was pumped to a Sharples P3400 Solid Bowl centrifuge at arate of approximately 15 gallons per minute and centrifuged atapproximately 4000 rpm. The solids cake from the centrifuge containsabout 30 to 45 percent solids and was pumped to a double drum dryer fordrying. The dried product had a moisture content of 5.7%. The color,taste, and texture were determined to be satisfactory. On a dry basis,the product had the following characteristics:

    ______________________________________                                        Protein           25.5%                                                       Total Dietary Fiber                                                                             45.4%                                                       Nitrogen Free Extract                                                                           23.6%                                                       Ash               3.1%                                                        Fat               2.4%                                                        Unconverted Starch                                                                              0.0%                                                        ______________________________________                                    

EXAMPLE TWO

Wheat was milled in a hammermill with an 8/64th inch screen and 3400pounds was added to water at 70 degrees F. Six hundred (600) pounds ofoat groats were similarly ground and added to the wheat and water slurryto produce a slurry having approximately 21% solids, of which 85% waswheat and 15% was oats. No calcium was added to aid hydrolysis. Theslurry was heated with live steam to a temperature of 120 degrees F andsix pounds of DEX-ZYME (0.15% by weight of grain) was added. Heating wascontinued to 180 degrees F over a period of 37 minutes and the steaminjection was stopped. At this point, a conventional starch iodine testindicated only a slight presence of starch with a Brix value of 18degrees. This indicated approximately 99% of the starch was removed. Theslurry was held at 180 degrees F for fifteen minutes and thereafterpumped to the centrifuge for the separation of solids. The solids cake,being again approximately 30 to 50% solids was pumped to a double drumdryer for drying.

It should be noted that the hydrolyzing enzyme was not taken to the"kill-point" by heating above 200 degrees F. Instead, the grains wereseparated and dried to 2.7% moisture to arrest hydrolysis while apresence of starch was indicated. Consequently, the starch content wassignificantly higher than the product of Example One.

The product on a dry matter basis was characterized as follows:

    ______________________________________                                        Ash                    3.1%                                                   Fat                    2.4%                                                   Protein                20.3%                                                  Total Dietary Fiber (AOAC method)                                                                    47.8%                                                  Soluble Dietary Fiber  9.4%                                                   Nitrogen-Free Extract  26.4%                                                  ______________________________________                                    

It should be noted that the "carbohydrates" or nitrogen-free extractmeasure includes both unconverted starch and residual sugars. Because ofthe higher carbohydrate content, the fiber and protein wasproportionately lower. The color of the product was somewhat lighter(more tan) than the all-wheat product with a slightly different, yetpleasing, taste due to the presence of the oats. The texture of theoat-wheat product was substantially the same in baking tests. It shouldbe particularly noted that this product contains a desirable balance ofsoluble fiber to insoluble fiber.

In order to provide for helpful comparisons between the reportedanalyses of the present invention and published analyses of grainproducts of some of the prior art, some explanations may be useful.Until recently, fiber was often reported as "crude" fiber (AOAC method7.071). Fiber analysis of the present invention uses the more moderntotal dietary fiber (AOAC method). Analysis of the same sample by thetwo different methods may result in a total dietary fiber a magnitude of3 to 4 times higher than "crude" fiber.

A way to correlate test results that can provide indirect comparisonsutilizes the calculated measure of nitrogen-free extract. Thepercentages of water, ash, protein, fiber and fat are simply addedtogether and the sum subtracted from 100 percent. Since nitrogen-freeextract is a calculated number consisting of the remainder ofconstituents after other analyses have been made, it can be useful incomparing crude fiber to total dietary fiber. If all other analyses arethe same, the increase in crude fiber related to total dietary fiber isreflected in a percentage decrease in nitrogen-free extract. Forexample, the results of the same corn DDGS sample analysis using twodifferent fiber methods are set forth below:

    __________________________________________________________________________                                  NITROGEN-                                       GRAIN  ASH FAT                                                                              PROTEIN                                                                             CRUDE FIBER                                                                             FREE EXTRACT                                    __________________________________________________________________________    Corn DDGS                                                                            10.1%                                                                             9.0%                                                                             23.0% 6.3%      51.6%                                           __________________________________________________________________________                        TOTAL DIETARY                                                                           NITROGEN-                                       GRAIN  ASH FAT                                                                              PROTEIN                                                                             FIBER     FREE EXTRACT                                    __________________________________________________________________________    Corn DDGS                                                                            10.1%                                                                             9.0%                                                                             23.0% 32.0%     25.9%                                           __________________________________________________________________________

It may be seen that the sum of crude fiber and nitrogen-free extract isthe same as the sum of total dietary fiber and nitrogen-free extract.Therefore, because of the conventional and consistent use ofnitrogen-free extract when reporting analyses, correlations betweenfiber measuring methods can easily be made.

Accordingly, the sum of fiber and nitrogen-free extract becomes a usefulcharacteristic of the present invention. It has been found that productsof the present invention have such a sum greater than 70%. Products ofthe prior art have such a sum less than 70%.

As discussed previously, many starch-bearing grains may be used in theprocess, and made into products of the present invention. Inasmuch asthe specific characteristics of the finished products depend greatly onthe selected whole grain degree of hydrolysis, and the selected amountof water in the grain slurry. The following tables set forth estimatedproduct characteristics for selected process variables within the scopeof the present invention. The following examples assume that the waterto grain ratio is constant and as described in Example One. The grainsolids content from the centrifuge is assumed to be 30 to 50% by weight.

When wheat is the grain of choice the anticipated preferredcharacteristics would be fiber content substantially between 45 and 60%,protein content substantially between 21 to 25% and nitrogen-freeextract content substantially between 19 to 28%, all by weight.

When a mixture of wheat and oats is the grain of choice the anticipatedpreferred characteristics would be fiber content substantially between44 to 49%, protein content substantially between 19 to 25% andnitrogen-free extract substantially between 21 to 28%, all by weight. Ifdesired, the ratio of wheat to oats could be adjusted to produce aproduct having a mixture of 20% soluble fiber and 80% insoluble fiber.When rice is the grain of choice the anticipated preferredcharacteristics would be fiber content substantially between 41 to 45%,protein content substantially between 20 to 23%, and nitrogen-freeextract substantially between 30 to 34% all by weight. When corn is thegrain of choice the anticipated preferred characteristics would be fibercontent substantially between 43 to 46% protein content substantiallybetween 1 to 24%, and nitrogen-free extract substantially between 26 to29% all by weight.

                                      TABLE I                                     __________________________________________________________________________    ANALYSIS AT 90% HYDROLYSIS                                                           NITROGEN                                                                              TOTAL TOTAL OF                                                        FREE EX-                                                                              DIETARY                                                                             NFE AND                                                                              RESIDUAL                                          GRAIN  TRACT (NFE)                                                                           FIBER FIBER  SUGAR  PROTEIN                                    __________________________________________________________________________    Rice   23.5%   41.0% 74.5%  23.5%  20.5%                                      Wheat  27.0%   45.0% 72.0%  17.0%  23.0%                                      Corn   29.1%   43.9% 73.0%  19.1%  22.0%                                      Wheat/Oats                                                                           27.7%   44.8% 72.5%  17.7%  22.5%                                      __________________________________________________________________________

                                      TABLE II                                    __________________________________________________________________________    ANALYSIS AT 98% HYDROLYSIS                                                           NITROGEN                                                                              TOTAL TOTAL OF                                                        FREE EX-                                                                              DIETARY                                                                             NFE AND                                                                              RESIDUAL                                          GRAIN  TRACT (NFE)                                                                           FIBER FIBER  SUGAR  PROTEIN                                    __________________________________________________________________________    Rice   30.5%   43.0% 73.5%  28.5%  21.5%                                      Wheat  24.6%   46.9% 71.5%  22.6%  23.5%                                      Corn   27.0%   45.3% 72.3%  25.0%  22.7%                                      Wheat/Oats                                                                           22.9%   48.0% 70.9%  20.9%  24.1%                                      __________________________________________________________________________

                                      TABLE III                                   __________________________________________________________________________    ANALYSIS AT 100% HYDROLYSIS                                                          NITROGEN      TOTAL OF                                                        FREE EX-                                                                              DIETARY                                                                             NFE AND                                                                              RESIDUAL                                          GRAIN  TRACT (NFE)                                                                           FIBER FIBER  SUGAR  PROTEIN                                    __________________________________________________________________________    Rice   30.0%   43.3% 73.3%  30.0%  21.7%                                      Wheat  23.6%   47.5% 71.1%  23.6%  23.9%                                      Corn   26.1%   45.7% 71.8%  26.1%  23.2%                                      Wheat/Oats                                                                           21.8%   48.7% 70.5%  21.8%  24.5%                                      __________________________________________________________________________

For comparison purposes, some of the grain products of the prior art areset forth in Table IV.

                                      TABLE IV                                    __________________________________________________________________________              NITROGEN      TOTAL OF                                                        FREE EX-                                                                              CRUDE NFE AND                                                         TRACT (NFE)                                                                           FIBER FIBER  PROTEIN                                        __________________________________________________________________________    DISTILLER'S                                                                   DRIED GRAINS                                                                  Corn      45.9%   9.9%  55.8%  28.6%                                          Rye       52.3%   12.5% 64.8%  26.4%                                          Wheat     45.1%   13.9% 59.0%  30.6%                                          BREWER'S                                                                      SPENT GRAINS                                                                  Barley    47.9%   19.9% 67.8%  21.9%                                          RASCO PATENT                                                                  # 4,828,846                                                                   Wheat DDGS                                                                              49.9%   6.8%  56.7%  33.9%                                          Corn DDGS 51.5%   6.3%  57.8%  23.0%                                          __________________________________________________________________________

The food product of the present invention is organolyptically suitablefor use in human foods, particularly as a component in baked goods,cereals (cooked or ready-to-eat), diet supplements, meat extenders,salad toppings, yogurt, and snack foods without the requirement ofreformulation. Baked goods include items such as breads, rolls,pancakes, muffins, cakes, cookies, tortillas, pastas and noodles. Incooking tests, products of the present invention have been substitutedfor flour in baked goods between 20 to 50% without loss of consumeracceptability. Bran muffins have been made at 100% substitution of flourwith the product of the present invention with only minimal loss ofacceptability.

From the foregoing, it would be appreciated that although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention.

We claim:
 1. A high fiber, high protein food product organolepticallysuitable for human consumption comprising:milled, starch-bearing cerealgrains having 90 to 100% of the starch enzymatically converted, saidconverted cereal grains having a protein content on a dry matter basissubstantially between 17 to 30% by weight, a total dietary fiber contenton a dry matter basis substantially between 30 to 70% by weight and anitrogen-free extract content on a dry matter basis of less than 40% byweight, said converted grains having a coating thereon of residualsugars from the enzymatic conversion of starch substantially between 10to 30% by weight on a dry matter basis, said sugars containing less than5% glucose.
 2. The food product of claim 1 wherein the nitrogen-freeextract content is less than 30% by weight.
 3. The food product of claim2 wherein the nitrogen-free extract content is less than 20% by weight.4. The food product of claim 1 wherein the residual sugar issubstantially between 18 to 22% by weight.
 5. The food product of claim1 wherein the total dietary fiber content is substantially between 41 to49% by weight.
 6. The food product of claim 1 wherein the cereal grainsare selected from the group consisting of wheat, oats, rice, corn,psyllium, millet, rye, pearled barley, sorghum, and mixtures andcombinations thereof.
 7. The food product of claim 6 wherein the cerealgrain is wheat and the fiber content is substantially between 45 to 60%by weight, the protein content is substantially between 21 to 25% byweight and the nitrogen-free extract content is substantially between 19to 28% by weight.
 8. The food product of claim 6 wherein the cerealgrain is a mixture of wheat and oats, the fiber content is substantiallybetween 44 to 49% by weight, the protein content is substantiallybetween 19 to 25% by weight and the nitrogen-free extract issubstantially between 21 to 28% by weight.
 9. The food product of claim6 wherein the cereal grain is rice, the fiber content is substantiallybetween 41 to 45% by weight, the protein content is substantiallybetween 20 to 23% by weight an the nitrogen-free extract issubstantially between 30 to 34% by weight.
 10. The food product of claim6 wherein the cereal grain is corn, the fiber content is substantiallybetween 43 to 46% by weight, the protein content is substantiallybetween 21 to 24% by weight and the nitrogen-free extract issubstantially between 26 to 29% by weight.
 11. The food product of claim8 wherein the fiber content is 20% soluble fiber and 80% insolublefiber.
 12. A process for producing a high protein, high fiber foodproduct organoleptically suitable for human consumption form selectedstarch-bearing cereal grains comprising the steps of:suspendingstarch-bearing cereal grains in a selected amount of water to form anaqueous slurry; heating the slurry sufficiently to at least partiallygelatinize the starch; liquefying and hydrolyzing a selected amountbetween 90 to 100% of the starch in the grains with enzymes to produce agrain mixture having a grain solids fraction and an aqueous sugarsfraction with a Brix value of substantially between 14 to 24 degrees,the sugars fraction containing less than 5% glucose; and separating thegrain solids fraction of the mixture from the aqueous sugars fraction tothe mixture to produce a substantially solids-free aqueous sugarsfraction and a grain solids cake with a solids content substantiallybetween 30 to 50% by weight and 50 to 70% sugars fraction by weight,said grain solids cake having a total dietary fiber content on a drymatter basis substantially between 30 to 70% by weight, a proteincontent on a dry basis of substantially between 17 to 30% and anitrogen-free extract content on a dry basis of less than 40% by weight.13. The process of claim 12 wherein the hydrolysis of the starch isirreversibly arrested before separating the grain solids by elevatingthe temperature of the grain mixture to a selected temperature above themaximum temperature tolerance level of the liquifying enzymes.
 14. Theprocess of claim 12 wherein the selected amount of the liquefied starchin the grains is between 90 to 98% and the hydrolysis of the starch isarrested by separating the grain solids fraction from the aqueous sugarsfraction to form a solids cake and drying the solids cake to a moisturecontent of less than 10% by weight.
 15. The process of claim 13 whereinthe selected temperature above the maximum temperature tolerance levelof the liquifying enzymes is between 190 degrees to 210 degrees F. 16.The process of claim 13 wherein the selected amount of hydrolyzed starchis 100%, the selected amount of water is sufficient to produce a Brixvalue of 17 to 19 degrees to produce a nitrogen-free extract content isless than 30%.
 17. The process of claim 12 wherein the separating ofgrain solids fraction from aqueous sugars fraction includes centrifugingthe grain mixture to produce a solids cake having a solids contentbetween 30 to 50% by weight.
 18. The process of claim 17 wherein theaqueous sugars fraction has a Brix value between 18 to 21 degrees and aratio of glucose to total sugars of less than substantially 1%.
 19. Theprocess of claim 12 wherein the cereal grains are selected from thegroup consisting of wheat, oats, corn, rice, psyllium, millet, rye,pearled barley, sorghum and mixtures thereof.
 20. The process of claim19 wherein the cereal is wheat, the aqueous slurry has a solids contentbetween 20 to 50% by weight, the hydrolysis is irreversibly arrested byheating to a temperature above 190 degrees F. when the selected amountof hydrolyzed starch is substantially 100%, the amount of glucose tototal sugars is less than substantially 1% by weight, and the aqueoussugars fraction has a Brix value of 17 to 19 degrees.
 21. The process ofclaim 20 wherein the separation of grain solids from the aqueous sugarsfraction includes centrifuging the grain mixture to produce a solidscake having a solids content between 30 to 50% by weight; anddrying thesolids cake to produce a food product having a nitrogen-free extractcontent less than 30% by weight on a dry basis and a total dietary fibercontent greater than 45% by weight on a dry basis and a protein contentsubstantially between 21 to 25% by weight on a dry basis.
 22. Theprocess of claim 15 wherein the selected amount of liquefied starch issubstantially between 90 to 98% by weight and the separating of thegrains solids fraction from the aqueous sugars fraction includescentrifuging the grains mixture to produce a solids cake having a solidscontent between 30 to 50% by weight, including the step of:drying thesolids cake to produce a food product having a protein content ofsubstantially between 21 to 25% by weight on a dry basis, a totaldietary fiber content between 45 to 60% by weight on a dry basis and anitrogen-free extract content substantially between 19 to 28% by weighton a dry basis.
 23. The process of claim 19 wherein the selected grainincludes a mixture of wheat and oats to produce a food product having amixture of soluble dietary fiber and insoluble dietary fiber.
 24. Theprocess of claim 12 further comprising the steps of:fermenting thesolids-free sugar fraction to produce an ethanol containing liquor; anddistilling the liquor to recover substantially pure fuel grade ethanol.25. The process of claim 24 further comprising the step of:enzymaticallyhydrolyzing the solids-free sugars fraction to at least partiallydegrade the higher sugars in the sugar fraction to glucose beforefermenting the solids-free sugar fraction.
 26. A food product made bythe process of claim
 13. 27. A food product made by the process of claim14.
 28. A food product made by the process of claim 20.